98FoRmULa_BiRd

My exhaust started making a weird sputtering sound when hitting the gas pedal. It sounded like it was coming from the manifold area and it started to get really annoying while driving. I have had my car for over 10 years so I know how its supposed to sound. I took my car to the exhaust shop to check for any exhaust leaks. They said it appeared to be the pipe right in front of the cat. They welded a flex pipe pre cat and the sputtering has stopped. My car actually seems to be much quieter then it used to be.

I am wondering if the flex pipe restricts any air flow pre cat? The width of the pipe looks the same. I plan on getting a new exhaust very soon (Mad Hammer) but I don't wanna mess with any airflow before the cat back gets installed.

ISU-WS6

It shouldn't cause any restrictions, but if they didn't use one with the interlock rings inside, high exhaust temps can cause the inner mesh to do weird **** and swell up. But I think that's mainly forced Induction that has that issue.